A debris ball found on a NSW South Coast beach. Photo: NSW EPA
Mysterious debris ‘balls’ found on Sydney and South Coast beaches in recent months likely came from Sydney Water’s sewage treatment plants.
That was the conclusion of an NSW Environment Protection Authority (EPA) investigation into the source of the debris balls.
And Sydney Water has been issued with an investigation notice to identify the exact source.
The EPA says a thorough scientific and technical investigation found similarities between the make-up of the debris balls and samples taken from some of Sydney’s major waste-water treatment plants, including those at Malabar and Bondi.
EPA Director Operations Adam Gilligan says the EPA issued an investigation notice to Sydney Water to pinpoint the precise source(s).
“This is a significant step forward in our investigation but there is still work to do,” Gilligan says.
“While we are yet to determine exactly what caused the pollution incidents to occur when they did, we can say the composition and the characteristics of the debris balls are consistent with a land-based sewage source.”
Under the notice, Sydney Water will have to model the dispersion of the debris balls, take and analyse samples at its sewage treatment plants and examine its deep ocean outfall systems and its sewerage pipe network.
Gilligan says a wastewater panel has been set up to provide independent scientific advice to the EPA and other NSW Government agencies. It will be led by Professor Stuart Khan, Head of School of Civil Engineering at the University of Sydney.
BACKGROUND
Debris balls found at beaches around Sydney and two South Coast beaches from October 2024 to January 2025 were sampled by the agency.
The EPA’s investigation expanded earlier this year after more balls were found on the South Coast and Northern Beaches.
Since October 2024, the balls were subject to extensive chemical analysis and found to contain fatty acids, petroleum hydrocarbons, organic and inorganic materials.
The EPA says the public community must not touch debris balls or any pollution they find on beaches and to immediately report new finds to their council or call 131 555.
